diff --git a/src/ci/mcp/Tools.groovy b/src/ci/mcp/Tools.groovy
new file mode 100644
index 0000000..2c1986f
--- /dev/null
+++ b/src/ci/mcp/Tools.groovy
@@ -0,0 +1,22 @@
+package ci.mcp
+
+/**
+ * https://issues.jenkins-ci.org/browse/JENKINS-26481
+ * fix groovy List.collect()
+ * Build command line options, e.g:
+ *    cmd_opts=["a=b", "c=d", "e=f"]
+ *    key = "--build-arg "
+ *    separator = " "
+ *    def options = getCommandBuilder(cmd_opts, key, separator)
+ *    println options
+ *    > --build-arg a=b --build-arg c=d --build-arg e=f
+ *
+ * @param options List of Strings (options that should be populated)
+ * @param keyOption key that should be added before each option
+ * @param separator Separator between key+Option pairs
+ */
+
+@NonCPS
+def getCommandBuilder(ArrayList options, String keyOption, String separator = " ") {
+  return options.collect{ keyOption + it }.join(separator).replaceAll("\n", "")
+}
diff --git a/src/ci/mcp/placeholder b/src/ci/mcp/placeholder
deleted file mode 100644
index e69de29..0000000
--- a/src/ci/mcp/placeholder
+++ /dev/null